This invention relates to a semiconductor device mounting and more specifically to a universally usable contact pattern for surface mounted semiconductor device die.
Semiconductor device die, such as flip chip surface mounted die and International Rectifier's DirectFET® packages described, for example in U.S. Pat. No. 6,624,522, carry die which have a particular planar contact pattern. Thus for MOSFET die, planar source, gate and drain contacts are presented, which must align to the respective contacts of an end user's or customer's circuit board. Other die will include diodes, IGBTs, and the like. The contact pattern on the die will differ in shape and number, depending on die size and current and voltage ratings.
The DirectFET package is a surface-mount package that improves MOSFET performance by lowering both the package's electrical and thermal resistance. The DirectFET package does so with a design that permits direct attachment of the die to a circuit board via solderable pads on the chip or die and through attachment to the interior of a copper or other conductive material drain clip that allows double-sided cooling. The die in the DirectFET package is a passivated die attached to a copper clip. Solderable metal contacts on the bottom of the die provide contacts such as gate and source contacts for a MOSFET to be mounted on and connected to a circuit board, while the copper clip provides an electrical connection to the MOSFET drain and permits topside cooling.
The circuit board pattern of contact locations is designed by each end user/customer to meet the contact pattern of the particular package. Thus, the circuit board will be designed with 2, 3, 4, 5, or any other number of spaced contacts of selected areas in some particular rectangular-like or mesh-like pattern.
The end user must then produce support board with surface contact patterns which match the number and pattern of the device to be mounted. Differences in the patterns and contact numbers increase the end-user's manufacturing process.